Operation Manual

Chapter II
MX 650 / MX 655
21
3. GENERAL DESCRIPTION
3.1. Battery installation and replacement
1. displayed when the voltage supplied by the
batteries is lower than the operating voltage.
2. Before changing the batteries, position the switch to
"OFF", unplug the measurement leads and disconnect
the clamp from the circuit being measured .
3. Using a Phillips screwdriver, loosen the 2 screws holding
the back of the case in place.
4. Replace the old battery with a new 9V battery, ensuring
that the polarity is respected.
5. Put the battery flap back in place and tighten the fixing
screws.
3.2. Zero function and relative measurement
This function is used to perform RCD measurements (in A, V
or Ω) by recording a "calibration value" which is subtracted
from the measurements.
To activate this function, press on the ∆
∆∆
∆REL button (the "
"
symbol is displayed).
The last value measured becomes the reference value which
will be subtracted from any subsequent measurements.
To display the reference value, press again on the ∆
∆∆
∆REL
button (the value is displayed and the " " symbol flashes).
To quit this function, press the zero button for 2 seconds.
3.3. Memory
It is possible to freeze the value displayed by pressing on the
"HOLD" button. To deactivate this function, press the "HOLD"
button a second time.
3.4. Automatic range
MX 650 and MX 655 multimeter clamps have automatic range
selection (Autorange).
On the MX 650 model, the range change can be "forced"
manually by holding the RANGE button down (the
manual range symbol appears).
The user can then choose the position of the decimal point
with short presses on the RANGE button.
To quit manual range, you must hold the RANGE button down
for at least 2 seconds; the clamp then returns to automatic
range selection mode.
3.5. Auto cut-off
The clamp shuts down automatically after 30 minutes if no
operations are performed ( symbol is displayed).
To deactivate this function, press and hold down the ∆
∆∆
∆REL
button. Then, switch the clamp on using the selector switch.
Release the button when a buzzing signal confirms the
manoeuvre (the symbol is no longer displayed).